Dear Rabbi Simon,
What is ideal time and latest-time to say an after-beracha?
Sometimes I’m eating and working (or learning, or other activity 🙂), and lose track of time.
Losing track of time…I know the feeling.
Ideally one should say a beracha acharona promptly when s/he finishes eating. However, one also should avoid a gratuitous beracha. So if you are working/learning/reading/watching/exercising and you are consuming a drink or snack, you may/should wait until you are finished before reciting a beracha acharona. This is true even if you refill your drink or snack over the course of time.
The “deadline” is generally regarded as 72 minutes after you finish eating. (The Sages reckoned that a person will still feel some satiation from eating until this amount of time has elapsed.) But since “time flies”, it is certainly better not to push it to the limit.
I hope this is clear enough. Bon appetit.
Rabbi Rashi Simon